1. Field of the Invention
The present invention relates to a child-resistant container closure system which provides easy opening by adults, even debilitated adults, but nevertheless requires manipulation which renders the closure resistant to opening by children. The present invention is composed of an easy-to-manufacture one-piece container and a closure for that container.
2. Discussion of the Prior Art
Child-resistant packaging is used to prevent inadvertent access by children to potentially dangerous materials such as medications, chemicals or poisons. Providing child-resistant packaging often adds cost and can result in the packaging being difficult for an adult user to open. This difficulty in opening child-resistant packaging is compounded when an adult attempting to open the package is debilitated or has reduced manual dexterity in one or more hands as a result of, e.g., arthritis. Elderly persons tend to rely on medication more than the average person, and also tend to have impaired manual strength and dexterity because of arthritis or age. Therefore, elderly persons can have a more difficult time opening child-resistant packaging.
Child-resistant packages exist in the prior art. For example, U.S. Pat. No. 3,917,097 to Uhlig describes a closure with internal flanges engaging abutments on the container. Disengagement of the abutments and flanges is accomplished by pressing opposing finger indentations to flex the flanges out of engagement with the abutments, and thereafter rotating the closure. Flexing of the flanges in this device requires deformation of the circumference of the closure by the user's fingers.
U.S. Pat. No. 3,984,021, also to Uhlig, and U.S. Pat. No. 3,941,268 to Owens et al. describe closures with internal tabs which engage abutments on the container. Again, disengagement of the tabs and abutments is accomplished by flexing opposing sides of the closure until the tabs and abutments disengage, and then rotating the closure. A similar concept is described in U.S. Pat. No. 3,993,208 to Ostrowsky. These devices also require flexing of the closure circumference to disengage the locking feature.
Finally, U.S. Pat. No. 5,230,433 to Hamilton et al. describes a closure with pawls which engage push-tab extensions projecting from a sleeve mounted on the container. Disengagement is accomplished by pressing the opposing push-tabs and rotating the closure.
Each of the above prior art closures suffer from at least the disadvantage that they are not easy to remove by debilitated adults, because they require significant force to flex the outer circumference of the closure portion to disengage the locking mechanisms between the closure and the container.
U.S. Pat. No. 4,948,002 and U.S. Pat. No. Design 330,677 also disclose child-resistant packages. These packages suffer from the disadvantage that the part of the package which must be manipulated to disengage the locking portion is on the container. As a result, the user must manipulate the container in one hand to disengage the locking feature, and must manipulate the closure in the other hand by rotating the closure to unscrew it from the container. Thus, manual dexterity in both hands is required to remove the closure, making the closure difficult to remove for those who may be more debilitated in one hand. These packages are also difficult to manufacture because they use a complicated two-piece container assembly as well as a one-piece closure assembly fitting on the container assembly.